(1) Field of the Invention
The present invention relates to a method of adhering unvulcanized rubber to vulcanized rubber through vulcanization.
(2) Description of the Prior Art
It is a commonly used means in rubber industry that an unvulcanized rubber is disposed on the surface of a vulcanized rubber and both the rubbers are adhered to each other through vulcanization, for example, in the retreading and partial repairing of tire, the endless adhesion and partial repairing of conveyer belt and rubber roller, the formation of fin on the belt surface, the production of weather strip and the like. In order to improve the adhesion of vulcanized rubber to unvulcanized rubber through vulcanization, there have hitherto been carried out the following treatments, for example, (1) the surface of a vulcanized rubber is buffer or shaved by a knife and the like to refresh the surface, and (2) the surface of a vulcanized rubber is treated with an organic acid or inorganic acid. However, in these treatments, the operation is troublesome, and the strength in the adhering portion is not always uniform. Further, sometimes the effect of these treatments does not sufficiently appear due to the variation of the properties of the vulcanized rubber itself with the lapse of time.